A total solar eclipse occurred at the Moon's descending node of orbit on Monday, December 14, 2020, with a magnitude of 1.0254. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's and the apparent path of the Sun and Moon intersect, blocking all direct sunlight and turning daylight into darkness; the Sun appears to be black with a halo around it. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 1.8 days after perigee (on December 12, 2020, at 20:40 UTC), the Moon's apparent diameter was larger.

Totality was visible from parts of southern Chile and Argentina. A partial eclipse was visible for parts of central and southern South America, Southern Africa, and Antarctica. A total solar eclipse crossed a similar region of the Earth about a year and a half earlier on July 2, 2019.

Totality made landfall in Puerto Saavedra, before traversing through portions of Araucanía Region, Los Ríos Region, and a very small part of Bío Bío Region. Cities in the path included Temuco, Villarrica, and Pucón. Totality was also visible on Mocha Island. The eclipse's path was similar to the solar eclipse of February 26, 2017. It occurred just 17 months after the solar eclipse of July 2, 2019 and, like the 2019 eclipse, was also visible from Chile and Argentina. It was also a partial solar eclipse in Bolivia, Brazil, Ecuador, Paraguay, Peru and Uruguay.

Totality was visible across the Northern Patagonia (specifically the provinces of Neuquén and Río Negro), passing through cities including Piedra del Águila, Sierra Colorada, Ministro Ramos Mexía, Junín de los Andes, and partially in San Martín de los Andes and San Carlos de Bariloche.

The ionospheric effects of the eclipse were expected to be monitored as part of the December 2020 Eclipse Festival of Frequency Measurement, a citizen science experiment organized through the Amateur Radio Science Citizen Investigation (HamSCI). Also, a prediction was made for a group of ionospheric stations in South America, using a numerical model (SUPIM-INPE), of the ionospheric response to this event.

Coincidentally, a comet belonging to the Kreutz sungrazer family called C/2020 X3 (SOHO) appeared during the eclipse, which later disintegrated shortly before reaching perihelion around the same day.

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the Moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.